1. Field of the Invention
This invention relates to a self configuring track controller for a diverter gate motor in a stacker area of a document sorting system.
2. Description of the Prior Art
In the past, track controllers for document sorting systems have possessed the limitation of requiring hardware individualization so that each track controller would "know" its sequential position in the system. This limitation complicated controller manufacture since the circuitry of the controller depended upon its position in the sorting system. Alternatively, prior controllers would be mass-produced but then individualized to their system position through wired connections performed at the site of operation. The customizing of the controller for its position in the document sorting system increased controller complexity and required time, personnel, and money in both the initial installation and subsequent maintenance of the system.
Recently, a patent to Sung, et al entitled, Document Sorting System Having Interchangeable Pocket Modules, U.S. Pat. No. 4,124,121, issued Nov. 7, 1978, disclosed a system which utilized a six bit binary code to identify the position of identical, interchangeable modules in a document sorting system. The first four bits of the binary code functioned as the module address while the remaining two bits indicated the module's pocket designated to receive a sorted document. Each module contained circuitry which incremented by one the four bit binary module address code and transmitted that value to the next downstream module. As a result, uniquely wired modules were no longer required.
The Sung, et al patent differs from the present invention in that the applicants' device deals only with the individual track controller for a diverter gate motor within each module. The track controller is responsive to a logic card identical with the logic cards of track controllers throughout the document sorting system. Unlike the Sung, et al patent, the applicants' invention does not deal here with controls or codes for the pockets in each module. Rather than relying on a four bit binary code for track controller position information, a number of binary, serial transitions of voltage levels are transmitted on a single data line from an upstream track controller to the next downstream track controller. The number of voltage transitions, incremented by one by each successive downstream track controller, relates to the sequential position of the track controller in the document sorting system. Additionally, each downstream track controller receives its position information twice to verify that the initially transmitted position information was proper. The Sung, et al patent disclosed no method of self-checking the correctness of module addresses.